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( A ) Transnasal 0-degree endoscopic view of frontal sinus seeker instrument (*) within the frontal outflow tract. ( B ) 70-degree transnasal. In A and B, the flexible endoscope (F) is visible, which was passed through choana coursing along anterior ethmoid cells to obtain a view into frontal recess shown in ( C ). Superior transorbital endoscopic view looking inferiorly into frontal recess visualizing the same instrument ( D ).
